TABLE 1.

Demographics and clinical characteristics of patients included in this study

Patient	Patient 1	Patient 2	Patient 3	Patient 4
Variable
Age at symptom onset	41	42	42	48
Presenting symptoms	Frontal	Frontal	Hemiparesis	Bulbar
Sex	Male	Female	Female	Male
Ethno‐regional descent	Nordic	Nordic	Nordic	Nordic
Mutation position	5:149435880	N/A	5:149435895	5:149435895
Mutation	Heterozygous c.2344C>T	N/A	Heterozygous c.2329C>T	Heterozygous c.2329C>T
Amino acid exchange	p. Arg782Cys	N/A	p. Arg777Trp	p. Arg777Trp
Diagnosis according to ALSP diagnostic criteria 5 , 8	Definitive 2a, 2b, 3, 4a	Possible 2a, 3, 4a	Definitive 2a, 2b, 3, 4a	Definitive 2a, 2b, 2c, 3, 4a
Mutation pathogenicity criteria 18	PS1 and PS3	N/A	PS1 and PS3	PS1 and PS3

Abbreviations: ALSP, adult leukoencephalopathy with spheroids and pigmented glia; Arg, arginine; CSF1R, colony stimulating factor 1 receptor (NM_005211.3); Cys, cysteine; N/A, not available; PS1, same amino acid change as a previously established pathogenic variant regardless of nucleotide change; PS3, well‐established in vitro or in vivo functional studies supportive of a damaging effect on the gene or gene product; Trp, tryptophan.